\documentclass[10pt]{letter} \usepackage{UPS_letterhead,xcolor,mhchem,mathpazo,ragged2e,} \newcommand{\alert}[1]{\textcolor{red}{#1}} \definecolor{darkgreen}{HTML}{009900} \usepackage[ colorlinks=true, citecolor=blue, breaklinks=true ]{hyperref} \urlstyle{same} \begin{document} \begin{letter}% {To the Editors of the Journal of Chemical Theory and Computation} \opening{Dear Editors,} \justifying Please find enclosed our manuscript entitled \textit{``A similarity renormalization group approach to Green's function methods''}, which we would like you to consider as a Regular Article in the \textit{Journal of Chemical Theory and Computation}. This contribution has never been submitted in total nor in parts to any other journal, and has been seen and approved by all authors. In the present contribution, we apply the similarity renormalization group (SRG) approach to the well-known $GW$ approximation of many-body perturbation theory. We show that the SRG transformation allows us to derive, from first principles, a new static and hermitian expression for the self-energy that can be directly employed in self-consistent $GW$ calculations. As shown on a large set of molecules, the resulting SRG-based regularized self-energy significantly accelerates the convergence of $GW$ calculations and improves the overall accuracy. We hope that these new technical developments will broaden the applicability of Green’s function methods in the molecular electronic structure community and beyond. Because of the novelty of this work and its potential impact in quantum chemistry and condensed matter physics, we expect it to be of interest to a wide audience within the chemistry and physics communities. We suggest Francesco Evangelista, Timothy Berkelbach, George Booth, Alexander Sokolov, and Xavier Blase as potential referees. We look forward to hearing from you soon. \closing{Sincerely, the authors.} \end{letter} \end{document}